More than six months in the making, I somehow ended up with enough capacitors and impressions to write something about it for those who might care. Initially, I set out to satisfy my curiosity regarding various caps with first-hand experience, and as such, these impressions are not meant to be the Bible or written in stone. Personal tastes, system synergy, and cycle of the Moon all apply. Don't be angry and e-mailing if my impressions don't quite match yours because well, that's why these things are very subjective.

What you see is my DIY capacitor burn-in setup w/ resistor and some of my caps. Various capacitors have spent weeks and weeks in the burner and gear before evaluation.
And now I present Part 2 of Capacitor Musings.

Epcos (Siemens Matsushita)
MKV B25834 polypropylene in oil capacitorEpcos
was founded by Siemens Matsushita, who sold all its interests in 2006.
MKV B25834 is a polypropylene in oil cap like the Siemens MKV radial
capacitor talked about previously. Mundorf silver/oil also happens to be
polypropylene in oil, so it was not a great surprise that Epcos sounded
somewhat similar to Mundorf silver/oil when directly substituted in
Mundorf's place. Not that they sounded the same, mind you, but both
shared a sense of liquidity and grace, which helped music just flow
effortlessly.

Compared
to silver/oil, Epcos had a bit more richness to voices and even more
apparent smoothness in the upper-midrange region, but it conceded some
sheer resolution and attack. Silver/oil sounded more like a "modern"
film capacitor while Epcos leaned more in the direction of paper-in-oil
caps without overt darkness or lack of resolution. I was especially glad
to observe Epcos not to possess overly rounded or slow bass like some
paper-in-oils can.

The Epcos, not surprisingly, sounds VERY much like the Siemens MKV
polypropylene in oil capacitor I described earlier. Both sound balanced,
if not extraordinarily extended or obviously "airy" up top. Human
voices have fluidity, richness, and sparkling liveliness that's so
endearing. If you are a die-hard Teflon or polystyrene fan, you will
likely call these poly oil caps a bit slower and not as lit-up, but the
fans of the poly oils will call it the opposite.

A
great strategy is to use the Epcos with something like Russian K72
Teflon cap somewhere else in the component. K72's enthusiastic, bold,
slightly upper-midrange-centric sound signature complements the ease of
Epcos very well while lending the whole package a dollop of Teflon
resolution. This combo sounds mighty nice, and I must thank "dweekie" for pointing me to these Epcos capacitors.

Fluorinert-Injected Russian K72 Teflon
capacitorFluorinert is an electrically insulating, inert
perfluorocarbon fluid developed by 3M as electronics coolant that some
have called "liquid Teflon."These K72 caps were injected with
Fluorinert by "Serengetiplains," who was gracious enough to let me
try them. Fluorinert K72 and regular K72 do sound different, but not
night-and-day different. After all, K72 possesses a very unique and
distinct sound one can recognize from a mile away.

What Fluorinert does seem to do is smooth out the
upper ranges somewhat while subduing the vividness and spice a dash. For
those who feel K72 is way too forward and brash for their tastes (I
don't...much), this will bring a welcome change, especially if your
system has too much sibilance with the stock K72. The changes brought on
by Fluorinert remind me of the sort of changes one hears when applying
damping material to equipment chassis. In fact, the changes are in the
similar direction as when I applied EAR isodamp material to the outside
of the K72, though Fluorinert seems to have even greater effect.

There are two issues with Fluorinert K72. One, it is
not commercially available, so you have to either DIY it yourself or ask
someone to make and sell it to you. Second, as one may guess from my
description, Fluorinert does decrease the apparent upper-air sparkle and
a certain"flair" of the stock K72 somewhat. If your personal tastes
or your equipment fancies to such personality of stock K72, then
Fluorinert may not necessarily sound "better" to you, proving once
again YMMV, etc.

Penta Labs TFT Teflon CapacitorWho is Penta Labs? I've heard the name in the
past, but mostly in relation to Penta Labs tubes. According to their
website, "Penta Laboratories is a Manufacturer and Distributor of
vacuum tubes, capacitors and electron tubes for Broadcast, Industrial,
Marine and Avionics applications worldwide." They also make a Teflon
capacitor which I am including here, but this is for general interest
only as the Penta cap available to me falls somewhere between my small
and large reference capacitance range.

In comparison to Russian Teflon capacitors, especially
the K72 and Fluorinert K72, Penta initially comes across as smoother and
more forgiving but also with less obvious sparkling detail and dynamic
pop. However, Penta seems to take forever to "settle into" a spot
after soldering (even after long burn-in before soldering), so continue
listening, and one realizes certain things just sound more "right,"
especially the piano and other instruments that have significant extreme
high-frequency harmonic content. These seem to have finer sonic pixels
compared to Russian Teflons, but each pixel is not as lit-up, if you can
picture that. Yet there's no denying they have tons of resolution and
purity, so the combination of supple richness and resolution forces you
to keep listening to music. In fact, Penta Labs kind of reminds me of
that denser, richer, more elegant
school
of Teflon sound possessed by Sonicap Platinum capacitors.

By the way, it appears Custom Capacitors Electronics
makes Penta Teflon, then according to their website, it must use
tetrafluoroethylene (TFE) film and aluminum foil, which makes perfect
sense since I seem to notice a consistent sonic pattern with aluminum
foil Teflon caps and tin foil Teflon caps, like VH Teflons. Based on
that, Aura-T Teflons I am currently listening to probably is tin foil...

Audience Aura-T Teflon CapacitorOh, boy, does this ever stop? It was almost easier
back in the day when you basically had only one Teflon capacitor to
choose from, the Relcap TFT Teflon capacitor, which is a fine capacitor.
Having lived with many different Teflon capacitors, I get the impression
that roughly 2 general "flavors" exist among the Teflon capacitors
available today. One I would call "electrostat flavor" and the other "cone flavor" because the former group reminds me of a great
electrostat speaker while the latter reminds me of a great dynamic cone
speaker. Formerly, only the VH Teflon belonged to the electrostat flavor
while the Russian K72, FT3, Sonicap Platinum, and Penta Labs belonged to
the cone flavor.

Well, now the Aura-T joins the VH Teflon in the
electrostat flavor. These caps set themselves apart from the others by
having an almost impossibly ethereal, pure, and extended top-end with
endless decay like only a good electrostat can. Sound has a see-through
transparency and zero veil, and there's not a spec of dirt, grime,
grit on that window. It's possible some people's tastes may prefer a
less see-through, more tactile density like a good dynamic speaker can
provide, but there's no question the ‘stat camp resolves more
information.

The cone flavor Teflon caps have a more forward
midrange presentation compared to mid-hall perspective of VH and Aura-T.
Some would call them "too forward," but this combined with
less-see-through boldness can make for some *very* involving musical
fun. No, these don't have as much forever-decaying, absolutely
feather-sweet extension and elegance, but in the right setup and
personal tastes, I can't blame you if you said you preferred this
school of sound.

Now, somebody must be wondering, "so which is
better, VH or Aura-T?" First of all, I am already using the
most-resolving transducer I know of (HE audio ‘stat) half an inch away
from my ears to get rid of any room interactions that will muddy up
evaluations using speakers. Even then, I would not bet any of my
hard-earned money on reliably telling them apart most of the time.

If somebody had a gun to my head, I *might* mutter
Aura-T may possibly have a thin hair's worth more sparkle and VH
Teflon may have gnat's fart's worth more midrange warmth. I'm sure
to some people that hair and fart will be a big deal in their
preferences, but please don't be using language like A "blows
away" B. Really...